Fas ligand regulates the immunomodulatory properties of dental pulp stem cells

Dental pulp stem cells (DPSCs) possess immunoregulatory properties, but the underlying mechanism is not fully understood. Here we showed that DPSCs were capable of inducing activated T-cell apoptosis in vitro and ameliorating inflammatory-related tissue injuries when systemically infused into a murine colitis model. Mechanistically, DPSC-induced immunoregulation was associated with the expression of Fas ligand (FasL), a transmembrane protein that plays an important role in inducing the Fas apoptotic pathway. Knockdown of FasL expression by siRNA in DPSCs reduced their capacity to induce T-cell apoptosis in vitro and abolished their therapeutic effects in mice with colitis. However, the expression level of FasL did not affect either DPSC proliferation rate or multipotent differentiation potential. In summary, FasL governs the immunoregulatory property of DPSCs in the context of inducing T-cell apoptosis.

Patterns of co-morbidity with anxiety disorders in Chinese women with recurrent major depression

BACKGROUND

Studies conducted in Europe and the USA have shown that co-morbidity between major depressive disorder (MDD) and anxiety disorders is associated with various MDD-related features, including clinical symptoms, degree of familial aggregation and socio-economic status. However, few studies have investigated whether these patterns of association vary across different co-morbid anxiety disorders. Here, using a large cohort of Chinese women with recurrent MDD, we examine the prevalence and associated clinical features of co-morbid anxiety disorders.

METHOD

A total of 1970 female Chinese MDD patients with or without seven co-morbid anxiety disorders [including generalized anxiety disorder (GAD), panic disorder, and five phobia subtypes] were ascertained in the CONVERGE study. Generalized linear models were used to model association between co-morbid anxiety disorders and various MDD features.

RESULTS

The lifetime prevalence rate for any type of co-morbid anxiety disorder is 60.2%. Panic and social phobia significantly predict an increased family history of MDD. GAD and animal phobia predict an earlier onset of MDD and a higher number of MDD episodes, respectively. Panic and GAD predict a higher number of DSM-IV diagnostic criteria. GAD and blood-injury phobia are both significantly associated with suicidal attempt with opposite effects. All seven co-morbid anxiety disorders predict higher neuroticism.

CONCLUSIONS

Patterns of co-morbidity between MDD and anxiety are consistent with findings from the US and European studies; the seven co-morbid anxiety disorders are heterogeneous when tested for association with various MDD features.

Pattern transfer nanomanufacturing using magnetic recording for programmed nanoparticle assembly

We report a novel nanomanufacturing technique that incorporates patterned arrays built entirely from Fe₃O₄ nanoparticles into a flexible and transparent polymer film. First, the nanoparticles are patterned using the enormous magnetic field gradients at the surface of commercial disk drive media, and then the resulting architecture is transferred to the surface of a polymer film by spin-coating and peeling. Since the particles are immobilized by the field gradients during the spin-coating process, the patterned array is preserved after peeling. To demonstrate the potential of this technology, we fabricate a 5 mm diameter all-nanoparticle diffraction grating capable of producing a white-light optical spectrum. We also demonstrate several extensions to this technology, where, by adding an external magnetic field during assembly, we create both periodic variations in topography, as well as a nanocomposite with two vertically and horizontally separated nanoparticle layers. As this technique leverages the nanometer resolution inherent in current magnetic recording technology, strong potential exists for low-cost nanomanufacturing of optical and electronic devices from a variety of nanomaterials with ∼10 nm resolution.

Perceived parenting and risk for major depression in Chinese women

BACKGROUND

In Western countries, a history of major depression (MD) is associated with reports of received parenting that is low in warmth and caring and high in control and authoritarianism. Does a similar pattern exist in women in China?

METHOD

Received parenting was assessed by a shortened version of the Parental Bonding Instrument (PBI) in two groups of Han Chinese women: 1970 clinically ascertained cases with recurrent MD and 2597 matched controls. MD was assessed at personal interview.

RESULTS

Factor analysis of the PBI revealed three factors for both mothers and fathers: warmth, protectiveness, and authoritarianism. Lower warmth and protectiveness and higher authoritarianism from both mother and father were significantly associated with risk for recurrent MD. Parental warmth was positively correlated with parental protectiveness and negatively correlated with parental authoritarianism. When examined together, paternal warmth was more strongly associated with lowered risk for MD than maternal warmth. Furthermore, paternal protectiveness was negatively and maternal protectiveness positively associated with risk for MD.

CONCLUSIONS

Although the structure of received parenting is very similar in China and Western countries, the association with MD is not. High parental protectiveness is generally pathogenic in Western countries but protective in China, especially when received from the father. Our results suggest that cultural factors impact on patterns of parenting and their association with MD.

Mesenchymal stem cells: a double-edged sword in regulating immune responses

Mesenchymal stem cells (MSCs) have been employed successfully to treat various immune disorders in animal models and clinical settings. Our previous studies have shown that MSCs can become highly immunosuppressive upon stimulation by inflammatory cytokines, an effect exerted through the concerted action of chemokines and nitric oxide (NO). Here, we show that MSCs can also enhance immune responses. This immune-promoting effect occurred when proinflammatory cytokines were inadequate to elicit sufficient NO production. When inducible nitric oxide synthase (iNOS) production was inhibited or genetically ablated, MSCs strongly enhance T-cell proliferation in vitro and the delayed-type hypersensitivity response in vivo. Furthermore, iNOS^−/− MSCs significantly inhibited melanoma growth. It is likely that in the absence of NO, chemokines act to promote immune responses. Indeed, in CCR5^−/−CXCR3^−/− mice, the immune-promoting effect of iNOS^−/− MSCs is greatly diminished. Thus, NO acts as a switch in MSC-mediated immunomodulation. More importantly, the dual effect on immune reactions was also observed in human MSCs, in which indoleamine 2,3-dioxygenase (IDO) acts as a switch. This study provides novel information about the pathophysiological roles of MSCs.

Non-exposed bisphosphonate-related osteonecrosis of the jaw: a critical assessment of current definition, staging, and treatment guidelines

Non-exposed bisphosphonate-related osteonecrosis of the jaw (BRONJ) is a newly reported complication arising from bisphosphonate therapy that presents with atypical symptoms and no apparent mucosal fenestration or exposure of necrotic bone. The clinical observation of the presence of necrotic bone underneath normal epithelial coverage was not conclusive for the diagnosis of BRONJ based on current guidelines established by the American Association of Oral and Maxillofacial Surgeons (AAOMS) and the American Society for Bone and Mineral Research (ASBMR), which specify the presence of clinically exposed necrotic bone for more than 8 weeks. Hence, the purpose of this review is to critically assess the current guidelines for diagnosis and management of BRONJ and propose a modified staging system and treatment guidelines to properly address the non-exposed variant of BRONJ lesions.

Pharmacokinetics, pharmacodynamics, and tolerability of a generic formulation of exenatide: a randomized, open-label, single- and multiple-dose study in healthy Chinese volunteers

A randomized, open-label, dose-escalating study was designed to assess the pharmacokinetics, pharmacodynamics and tolerability of single and multiple subcutaneous administrations of exenatide in 24 healthy Chinese volunteers. The effects of gender on the pharmacokinetics of exenatide were also evaluated. Subjects were randomized to receive a single and multiple subcutaneous doses of 5 or 10 μg of exenatide. Following the single dose subjects received exenatide twice daily on days 2-4 and once on day 5. Sequential blood samples were collected at regular intervals from 0 to 8 h after single administration. Concomitantly the serum glucose concentrations were measured in each sample. Tolerability was assessed using physical examination, vital signs, laboratory analysis, and by interview of subjects. Pharmacokinetic parameters for exenatide after subcutaneous administration of a single dose of 5-10 μg were as follows: Cmax=77.7 (13.9) and 136.1 (15.2) pg/mL; AUC0-t=184.2 (49.7) and 309.7 (52.3) pg·h/mL; AUC0-∞=225.8 (77.4) and 365.4 (68.8) pg·h/mL; tmax (median [range])=1.00 (0.75-1.50) and 1.00 (0.75-1.50) h; t1/2 (mean [range])=1.4 (0.7-3.2) and 1.8 (1.0-2.5) h, respectively. Because of its short t1/2, Css, min could not be detected in any plasma samples prior to daily dosing on days 3-5. Pharmacokinetic parameters for exenatide after administration of multiple doses of 5 or 10 μg were as follows: Cmax=81.2 (12.2) and 144.5 (13.3) pg/mL; AUC0-t=181.1 (39.4) and 275.6 (45.0) pg·h/mL; AUC0-∞=217.2 (44.8) and 313.3 (48.4) pg·h/mL; tmax=1.10 (0.75-1.25) and 1.00 (1.00-1.25) h; t1/2=1.6 (0.8-2.2) and 1.4 (0.9-2.7) h, respectively. Both doses of exenatide were associated with significant reductions in serum glucose concentrations (P<0.001) when compared to baseline levels. Mean percentage of maximal decline for serum glucose concentrations after single and multiple doses were 15.6% and 19.9% for 5 μg, respectively; as well as 26.3% and 28.7% for 10 μg, respectively. 12 of the 24 subjects reported a total of 75 adverse events. The rate increased with higher doses of exenatide: after 5 μg only one subject experienced at least 1 adverse event but following 10 μg 11 subjects were affected. 2 subjects receiving the higher dose of 10 μg exenatide dropped out because of adverse events (nausea and vomiting). The most common adverse events were of gastrointestinal origin (e. g. decreased appetite, nausea and vomiting) and of mild severity. In conclusion, in healthy Chinese subjects, AUC and Cmax increased in proportion to the dose, whereas t1/2 was independent of dose. The pharmacokinetic parameters after multiple dosing were consistent with those after single doses. No significant gender differences were noted for pharmacokinetic variables. Both exenatide doses were associated with significant reductions in serum glucose levels. Adverse events were mainly of gastrointestinal origin and their incidence was dose-dependent.

Childhood sexual abuse and the risk for recurrent major depression in Chinese women

BACKGROUND

Studies in Western countries have repeatedly shown that women with a history of childhood sexual abuse (CSA) are at increased risk for developing major depression (MD). Would this relationship be found in China?

METHOD

Three levels of CSA (non-genital, genital, and intercourse) were assessed by self-report in two groups of Han Chinese women: 1970 clinically ascertained with recurrent MD and 2597 matched controls. Diagnostic and other risk factor information was assessed at personal interview. Odds ratios (ORs) were calculated by logistic regression and regression coefficients by linear or Poisson regression.

RESULTS

Any form of CSA was significantly associated with recurrent MD [OR 3.26, 95% confidence interval (CI) 1.95-5.45]. This association strengthened with increasing CSA severity: non-genital (OR 2.47, 95% CI 1.17-5.23), genital (OR 2.77, 95% CI 1.32-5.83) and intercourse (OR 13.35, 95% CI 1.83-97.42). The association between any form of CSA and MD remained significant after accounting for parental history of depression, childhood emotional neglect (CEN), childhood physical abuse (CPA) and parent-child relationship. Among the depressed women, those with CSA had an earlier age of onset, longer depressive episodes and an increased risk for generalized anxiety disorder (GAD; OR 1.92, 95% CI 1.39-2.66) and dysthymia (OR 2.16, 95% CI 1.52-3.09).

CONCLUSIONS

In Chinese women CSA is strongly associated with MD and this association increases with greater severity of CSA. Depressed women with CSA have an earlier age of onset, longer depressive episodes and increased co-morbidity with GAD and dysthymia. Although reporting biases cannot be ruled out, our results are consistent with the hypothesis that, as in Western countries, CSA substantially increases the risk for MD in China.

MR Imaging Findings of Giant Trichilemmal Carcinoma on the Scalp. A Case Report

We describe the magnetic resonance imaging findings of a huge trichilemmal carcinoma (TLC) on the parietal and occipital region of the scalp in one patient. Our aim is to discuss the clinical, radiologic, and pathologic features of scalp TLC and to review relevant literature regarding this tumor. One patient with recent rapid tumor growth in the parietal and occipital region of the scalp underwent MR studies and subtotal resection. The tumor was seen as a poorly marginated and lobulated soft-tissue mass with isointense signal on T1-weighted images and hyperintense signal on T2-weighted images. Necrosis and ulceration were also found on the tumor surface. The TLC has been massively invading the nearby skull, meninges, brain tissue, and superior sagittal sinus. After exhibiting contrast, the tumor showed significant enhancement, with small portions remaining unenhanced. Subtotal excision of the mass and reconstruction of the scalp were performed. Microscopically, the mass was composed of trabecular growth of tumor cells with clear cytoplasm, prominent nucleoli, frequent mitoses, and foci of trichilemmal keratinization. Tumor on the scalp with heterogeneous, mixed signals on T2-weighted images, significant enhancement of solid portion, and local infiltration accompanied by surface deep ulceration may indicate a TLC. Wide surgical excision with tumor-free margins remains the best choice for treatment.

Basic fibroblast growth factor inhibits osteogenic differentiation of stem cells from human exfoliated deciduous teeth through ERK signaling

OBJECTIVE

Stem cells from human exfoliated deciduous teeth (SHED) are a unique postnatal stem cell population capable of regenerating mineralized tissue and treating immune disorders. However, the mechanism that controls SHED differentiation is not fully understood. Here, we showed that basic fibroblast growth factor (bFGF) treatment attenuated SHED-mediated mineralized tissue regeneration through activation of the extracellular signal-regulated kinase (ERK) 1/2 pathway.

MATERIAL AND METHOD

The level of mineralized nodule formation was assessed by alizarin red staining. Expression levels of osteogenic genes, osteocalcin and runt-related transcription factor 2, were examined by RT-PCR. Subcutaneous implantation approach was used to assess in vivo bone formation. Downstream signaling pathways of bFGF were examined by Western blotting.

RESULT

Activation of ERK1/2 signaling by bFGF treatment inhibited WNT/β-catenin pathway, leading to osteogenic deficiency of SHED. ERK1/2 inhibitor treatment rescued bFGF-induced osteogenic differentiation deficiency.

CONCLUSION

These data suggest that bFGF inhibits osteogenic differentiation of SHED via ERK1/2 pathway. Blockade ERK1/2 signaling by small molecular inhibitor treatment improves bone formation of SHED after bFGF treatment.

CD34 positive cells seeded on small caliber man-made vascular grafts exhibit increased antithrombogenic property compared with unfractioned mononuclear cells

AIM

The aim of this study was to compare the therapeutic potential of purified CD34+ cells with that of unfractioned mononuclear cells (MNCs) for the antithrombogenic property after seeding on the small caliber man-made grafts.

METHODS

Unfractioned MNCs and CD34+ cells were isolated from canine bone marrow. Differentiation of CD34 cells and unfractioned MNCs into endothelial cells were examined by CD31and vWF immunohistochemistry or immunofluorescence stain, endothelial cell function were evaluated via low-density lipoprotein (ac-LDL) - DiL incorpration and in vitro angiogenesis assay. Platelet adhesion assay was performed to determine antiplatelet adhesion property of the cells in vitro. Equal number of both cells were seeded onto the luminal surface of small caliber man-made grafts and implanted to replace a segment of common carotid artery. At different time points (24 h, 72 h, and 1 week) the grafts were retrieved. HE staining and SEM exam were performed.

RESULTS

CD34+ cells acquired significantly more CD31 and VWF expression, increased angiogenic potential and low-density lipoprotein (ac-LDL) incorporation compared to unfractioned MNCs under the induction of VEGF. More platelets were found to adhere to the surface of unfractioned MNCs group than to the CD34+ cell group. In vivo study demonstrated that more platelet adhesion and thrombus formation were observed in the unfractioned MNCs group rather than the CD34+ group. All the grafts in both groups were patent after implantation, except one graft seeded with unfractioned MNCs, occluded at 1 week. Statistically lower ratio of thrombi was found in the CD34+ cell seeding group at 24 h and 1 week after implantation, compared with the unfractioned MNCs one (P<0.05).

CONCLUSION

CD34+ cell exerted better antithrombogenic property than unfractioned MNCs after seeding onto the small caliber vessel grafts.

Mouse mandible contains distinctive mesenchymal stem cells

Although human orofacial bone-marrow-derived mesenchymal stem cells showed differentiation traits distinctly different from those of mesenchymal stem cells (MSCs) derived from long bone marrow (BMMSCs), mouse MSCs derived from orofacial bone have not been isolated due to technical difficulties, which in turn precludes the use of mouse models to study and cure orofacial diseases. In this study, we developed techniques to isolate and expand mouse orofacial bone/bone-marrow-derived MSCs (OMSCs) from mandibles and verified their MSC characteristics by single-colony formation, multi-lineage differentiation, and in vivo tissue regeneration. Activated T-lymphocytes impaired OMSCs via the Fas/Fas ligand pathway, as occurs in BMMSCs. Furthermore, we found that OMSCs are distinct from BMMSCs with respect to regulating T-lymphocyte survival and proliferation. Analysis of our data suggests that OMSCs are a unique population of MSCs and play an important role in systemic immunity.

ABBREVIATIONS

BMMSC, bone marrow mesenchymal stem cell; HA/TCP, hydroxyapatite/tricalcium phosphate; OMSC, orofacial mesenchymal stem cell; OVX, ovariectomized.

Transplantation of umbilical cord mesenchymal stem cells alleviates lupus nephritis in MRL/lpr mice

Systemic lupus erythematosus (SLE) is a multisystem autoimmune disease, which, despite the advances in immunosuppressive medical therapies, remains potentially fatal in some patients, especially in treatment-refractory patients. This study found that transplantation of umbilical cord mesenchymal stem cells (UC-MSCs) has the same therapeutic effect as transplantation of bone marrow mesenchymal stem cells (BM-MSCs), which has been reported to be efficient in treating SLE-related symptoms in MRL/lpr mice. Multi-treatment (at the 18th, 19th, and 20th weeks of age) of 1 × 10(6) UC-MSCs was able to decrease the levels of 24-h proteinuria, serum creatinine, and anti-double-stranded DNA (dsDNA) antibody, and the extent of renal injury such as crescent formation in MRL/lpr mice. A lower, but still significant, reduction in these parameters was also observed in mice receiving a single dose of UC-MSCs (at the 18th week). UC-MSCs treatment also inhibited expression of monocyte chemotactic protein-1 (MCP-1) and high-mobility group box 1 (HMGB-1) expression in a similar fashion. UC-MSCs labeled with carboxyfluorescein diacetate succinimidyl ester (CFSE) were found in the lungs and kidneys 1 week post infusion. In addition, after 11 weeks post UC-MSCs infusion, human cells were found in kidney of UC-MSCs-treated mice. These findings indicated that UC-MSCs transplantation might be a potentially promising approach in the treatment of lupus nephritis, possibly by inhibiting MCP-1 and HMGB-1 production.

Utility of PDL progenitors for in vivo tissue regeneration: a report of 3 cases

OBJECTIVE

Periodontal disease is an inflammatory disorder with widespread morbidities involving both oral and systemic health. The primary goal of periodontal treatment is the regeneration of the lost or diseased periodontium. In this study, we retrospectively examined feasibility and safety of reconstructing the periodontal intrabony defects with autologous periodontal ligament progenitor (PDLP) implantation in three patients.

MATERIALS AND METHODS

In this retrospective pilot study, we treated 16 teeth with at least one deep intrabony defect of probing depth (PD) > OR = 6 mm with PDLP transplantation and evaluated clinical outcome measures in terms of probing depth, gingival recession and attachment gain for a duration of 32-72 months. Furthermore, we compare PDLPs with standard PDL stem cells (PDLSCs) and confirmed that PDLPs possessed progenitor characters.

RESULTS

Clinical examination indicated that transplantationof PDLPs may provide therapeutic benefit for the periodontal defects. All treated patients showed no adverse effects during the entire course of follow up. We also found that PDLPs were analogous to PDLSCs in terms of high proliferation, expression of mesenchymal surface molecules, multipotent differentiation, and in vivo tissue regain. However, PDLPs failed to express scleraxis, a marker of tendon, as seen in PDLSCs.

CONCLUSIONS

This study demonstrated clinical and experimental evidences supporting a potential efficacy and safety of utilizing autologous PDL cells in the treatment of human periodontitis.

SHED differentiate into functional odontoblasts and endothelium

Studies on mechanisms underlying the differentiation of dental pulp stem cells are critical for the understanding of the biology of odontogenesis and for dental tissue engineering. Here, we tested the hypothesis that stem cells from exfoliated deciduous teeth (SHED) differentiate into functional odontoblasts and endothelial cells. SHED were seeded in tooth slice/scaffolds and implanted subcutaneously into immunodeficient mice. SHED differentiated into functional odontoblasts that generated tubular dentin, as determined by tetracycline staining and confocal microscopy. These cells also differentiated into vascular endothelial cells, as determined by beta-galactosidase staining of LacZ-tagged SHED. In vitro, vascular endothelial growth factor (VEGF) induced SHED to express VEGFR2, CD31, and VE-Cadherin (markers of endothelium) and to organize into capillary-like sprouts. VEGF induced ERK and AKT phosphorylation (indicative of differentiation), while inhibiting phosphorylation of STAT3 (indicative of 'stemness'). Collectively, this work demonstrates that SHED can differentiate into angiogenic endothelial cells and odontoblasts capable of generating tubular dentin.

Dentin-derived BMP-2 and Odontoblast Differentiation

It is known that stem cells from exfoliated deciduous teeth (SHED) can be induced to differentiate into odontoblasts. However, the nature of dentin-derived morphogenic signals required for dental pulp stem cell differentiation remains unclear. The hypothesis underlying this work is that dentin-derived Bone Morphogenetic Proteins (BMP) are necessary for the differentiation of SHED into odontoblasts. We observed that SHED express markers of odontoblastic differentiation (DSPP, DMP-1, MEPE) when seeded in human tooth slice/scaffolds and cultured in vitro, or implanted subcutaneously into immunodeficient mice. In contrast, SHED cultured in deproteinized tooth slice/scaffolds, or scaffolds without a tooth slice, do not express these markers. SHED express the BMP receptors BMPR-IA, BMPR-IB, and BMPR-II. Notably, blockade of BMP-2 signaling inhibited the expression of markers of odontoblastic differentiation by SHED cultured in tooth slice/scaffolds. Collectively, this work demonstrates that dentin-derived BMP-2 is required to induce the differentiation of SHED into odontoblasts.

Integration of silicon nanocrystals and erbium ring cavities for a silicon pumped Er:SiO2 laser

In this work we present a novel two-stage approach to achieve electrically pumped lasing on a CMOS compatible material platform in the telecom region. The proposed design consists of an electrically pumped silicon nanocrystal (Si-nc) light source acting as an optical pump for an Erbium doped silicate (Er:SiO2) lasing cavity. The integrated design, based on concentric disks of Si-nc and Er:SiO2, provides a means of coupling the Si-nc pump signal to the Er ions without requiring overlap of the Er based lasing mode with the Si-nc material. We present an electromagnetic analysis of the pump and lasing modes in the proposed configuration. We also present fabrication and characterization of Si-nc and Er:SiO2 microdisks as components of the integrated design.